From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-13.6 required=3.0 tests=BAYES_00,DKIM_INVALID, DKIM_SIGNED,HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_CR_TRAILER,INCLUDES_PATCH, MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS autolearn=ham autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id F3E9BC4361B for ; Tue, 15 Dec 2020 15:54:16 +0000 (UTC) Received: from hemlock.osuosl.org (smtp2.osuosl.org [140.211.166.133]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPS id 9224522582 for ; Tue, 15 Dec 2020 15:54:16 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 9224522582 Authentication-Results: mail.kernel.org; dmarc=fail (p=none dis=none) header.from=redhat.com Authentication-Results: mail.kernel.org; spf=pass smtp.mailfrom=iommu-bounces@lists.linux-foundation.org Received: from localhost (localhost [127.0.0.1]) by hemlock.osuosl.org (Postfix) with ESMTP id 4B5A3875F3; Tue, 15 Dec 2020 15:54:16 +0000 (UTC) X-Virus-Scanned: amavisd-new at osuosl.org Received: from hemlock.osuosl.org ([127.0.0.1]) by localhost (.osuosl.org [127.0.0.1]) (amavisd-new, port 10024) with ESMTP id pP6fl2qzn3CG; Tue, 15 Dec 2020 15:54:15 +0000 (UTC) Received: from lists.linuxfoundation.org (lf-lists.osuosl.org [140.211.9.56]) by hemlock.osuosl.org (Postfix) with ESMTP id 7E16E87134; Tue, 15 Dec 2020 15:54:15 +0000 (UTC) Received: from lf-lists.osuosl.org (localhost [127.0.0.1]) by lists.linuxfoundation.org (Postfix) with ESMTP id 6223FC088E; Tue, 15 Dec 2020 15:54:15 +0000 (UTC) Received: from fraxinus.osuosl.org (smtp4.osuosl.org [140.211.166.137]) by lists.linuxfoundation.org (Postfix) with ESMTP id 4128CC013B for ; Tue, 15 Dec 2020 15:54:14 +0000 (UTC) Received: from localhost (localhost [127.0.0.1]) by fraxinus.osuosl.org (Postfix) with ESMTP id 38F8084995 for ; Tue, 15 Dec 2020 15:54:14 +0000 (UTC) X-Virus-Scanned: amavisd-new at osuosl.org Received: from fraxinus.osuosl.org ([127.0.0.1]) by localhost (.osuosl.org [127.0.0.1]) (amavisd-new, port 10024) with ESMTP id 4wt0rsTc96jg for ; Tue, 15 Dec 2020 15:54:13 +0000 (UTC) X-Greylist: domain auto-whitelisted by SQLgrey-1.7.6 Received: from us-smtp-delivery-124.mimecast.com (us-smtp-delivery-124.mimecast.com [216.205.24.124]) by fraxinus.osuosl.org (Postfix) with ESMTPS id 41DF1848ED for ; Tue, 15 Dec 2020 15:54:13 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1608047651; h=from:from:reply-to:subject:subject:date:date:message-id:message-id: to:to:cc:cc:mime-version:mime-version:content-type:content-type: content-transfer-encoding:content-transfer-encoding: in-reply-to:in-reply-to:references:references; bh=tPEqUf9K/9QpL3MMNAVvudGcFr4JwyB646HzAagpF+Q=; b=aS95BRmN62TySJIblZRYPGlFEMwqIDRr1LfzD8/6l1Rng4f4kAE3grU7ee2W2dRN/o8WNm qz+De8UqC6WIMZMeTm49+I31qRnWZ00MSaBGxhV9BGmX7gZKyuQjij+DfKBfe40dc336pj vUsWQ+whTwKsmC6z5t6q5ff45OcH2WA= Received: from mimecast-mx01.redhat.com (mimecast-mx01.redhat.com [209.132.183.4]) (Using TLS) by relay.mimecast.com with ESMTP id us-mta-441-XRpPflBjPsmL5JDWg5sD-Q-1; Tue, 15 Dec 2020 10:54:06 -0500 X-MC-Unique: XRpPflBjPsmL5JDWg5sD-Q-1 Received: from smtp.corp.redhat.com (int-mx01.intmail.prod.int.phx2.redhat.com [10.5.11.11]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by mimecast-mx01.redhat.com (Postfix) with ESMTPS id 6C2A7192CC41; Tue, 15 Dec 2020 15:54:03 +0000 (UTC) Received: from x1.home (ovpn-112-193.phx2.redhat.com [10.3.112.193]) by smtp.corp.redhat.com (Postfix) with ESMTP id 917E81962E; Tue, 15 Dec 2020 15:54:00 +0000 (UTC) Date: Tue, 15 Dec 2020 08:53:59 -0700 From: Alex Williamson To: zhukeqian Subject: Re: [PATCH 4/7] vfio: iommu_type1: Fix missing dirty page when promote pinned_scope Message-ID: <20201215085359.053e73ed@x1.home> In-Reply-To: References: <20201210073425.25960-1-zhukeqian1@huawei.com> <20201210073425.25960-5-zhukeqian1@huawei.com> <20201214170459.50cb8729@omen.home> Organization: Red Hat MIME-Version: 1.0 X-Scanned-By: MIMEDefang 2.79 on 10.5.11.11 Cc: jiangkunkun@huawei.com, Andrew Morton , kvm@vger.kernel.org, Suzuki K Poulose , Marc Zyngier , Cornelia Huck , linux-kernel@vger.kernel.org, Sean Christopherson , Alexios Zavras , iommu@lists.linux-foundation.org, Mark Brown , James Morse , Julien Thierry , Catalin Marinas , wanghaibin.wang@huawei.com, Thomas Gleixner , Will Deacon , kvmarm@lists.cs.columbia.edu, linux-arm-kernel@lists.infradead.org, Robin Murphy X-BeenThere: iommu@lists.linux-foundation.org X-Mailman-Version: 2.1.15 Precedence: list List-Id: Development issues for Linux IOMMU support List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Errors-To: iommu-bounces@lists.linux-foundation.org Sender: "iommu" On Tue, 15 Dec 2020 17:37:11 +0800 zhukeqian wrote: > Hi Alex, > > On 2020/12/15 8:04, Alex Williamson wrote: > > On Thu, 10 Dec 2020 15:34:22 +0800 > > Keqian Zhu wrote: > > > >> When we pin or detach a group which is not dirty tracking capable, > >> we will try to promote pinned_scope of vfio_iommu. > >> > >> If we succeed to do so, vfio only report pinned_scope as dirty to > >> userspace next time, but these memory written before pin or detach > >> is missed. > >> > >> The solution is that we must populate all dma range as dirty before > >> promoting pinned_scope of vfio_iommu. > > > > Please don't bury fixes patches into a series with other optimizations > > and semantic changes. Send it separately. > > > OK, I will. > > >> > >> Signed-off-by: Keqian Zhu > >> --- > >> drivers/vfio/vfio_iommu_type1.c | 18 ++++++++++++++++++ > >> 1 file changed, 18 insertions(+) > >> > >> diff --git a/drivers/vfio/vfio_iommu_type1.c b/drivers/vfio/vfio_iommu_type1.c > >> index bd9a94590ebc..00684597b098 100644 > >> --- a/drivers/vfio/vfio_iommu_type1.c > >> +++ b/drivers/vfio/vfio_iommu_type1.c > >> @@ -1633,6 +1633,20 @@ static struct vfio_group *vfio_iommu_find_iommu_group(struct vfio_iommu *iommu, > >> return group; > >> } > >> > >> +static void vfio_populate_bitmap_all(struct vfio_iommu *iommu) > >> +{ > >> + struct rb_node *n; > >> + unsigned long pgshift = __ffs(iommu->pgsize_bitmap); > >> + > >> + for (n = rb_first(&iommu->dma_list); n; n = rb_next(n)) { > >> + struct vfio_dma *dma = rb_entry(n, struct vfio_dma, node); > >> + unsigned long nbits = dma->size >> pgshift; > >> + > >> + if (dma->iommu_mapped) > >> + bitmap_set(dma->bitmap, 0, nbits); > >> + } > >> +} > > > > > > If we detach a group which results in only non-IOMMU backed mdevs, > > don't we also clear dma->iommu_mapped as part of vfio_unmap_unpin() > > such that this test is invalid? Thanks, > > Good spot :-). The code will skip bitmap_set under this situation. > > We should set the bitmap unconditionally when vfio_iommu is promoted, > as we must have IOMMU backed domain before promoting the vfio_iommu. > > Besides, I think we should also mark dirty in vfio_remove_dma if dirty > tracking is active. Right? There's no remaining bitmap to mark dirty if the vfio_dma is removed. In this case it's the user's responsibility to collect remaining dirty pages using the VFIO_DMA_UNMAP_FLAG_GET_DIRTY_BITMAP support in the VFIO_IOMMU_UNMAP_DMA ioctl. Thanks, Alex > >> + > >> static void promote_pinned_page_dirty_scope(struct vfio_iommu *iommu) > >> { > >> struct vfio_domain *domain; > >> @@ -1657,6 +1671,10 @@ static void promote_pinned_page_dirty_scope(struct vfio_iommu *iommu) > >> } > >> > >> iommu->pinned_page_dirty_scope = true; > >> + > >> + /* Set all bitmap to avoid missing dirty page */ > >> + if (iommu->dirty_page_tracking) > >> + vfio_populate_bitmap_all(iommu); > >> } > >> > >> static bool vfio_iommu_has_sw_msi(struct list_head *group_resv_regions, > > > > . > > > _______________________________________________ iommu mailing list iommu@lists.linux-foundation.org https://lists.linuxfoundation.org/mailman/listinfo/iommu